I. Field
The following description relates generally to communication systems, and more particularly to a multichannel architecture for high throughput modems.
II. Background
In order to address the issue of increasing bandwidth requirements that are demanded for wireless communications systems, different schemes are being developed to allow multiple user terminals to communicate with a single access point by sharing the channel resources while achieving high data throughputs. Multiple Input or Multiple Output (MIMO) technology represents one such approach that has recently emerged as a popular technique for the next generation communication systems. MIMO technology has been adopted in several emerging wireless communications standards such as the Institute of Electrical Engineers (IEEE) 802.11 standard. IEEE 802.11 denotes a set of Wireless Local Area Network (WLAN) air interface standards developed by the IEEE 802.11 committee for short-range communications (e.g., tens of meters to a few hundred meters).
Next generation WLAN are targeting data rates that are over one (1) Gigabits per second (Gbps). One of the key enabling technologies is “multi-channel transmission,” which is aimed to increase the bandwidth to multiple channels and thereby improve throughput. Unlike other systems, achieving “multi-channel transmission” is not straightforward for several reasons. For example, devices may need to operate in asynchronous fashion in different channels, and the channels may become “de-sensed” in receive mode as a result of transmissions on the channels that are in transmit mode. Specifically, in some cases, the transmit signal in the transmit channel of the modem can be more than 100 dB stronger compared to the received signal in the received channel of the modem. Such a strong transmit signal can saturate the front-end of the receiver in the same modem, and cause non-linearities, thereby degrading the signal quality at the receiver. Another concern with multichannel modems is that the transmitted signal can become “aliased” into the received signal after analog to digital (ADC) conversion. This aliasing can degrade the signal quality at the receiver.
Consequently, it would be desirable to address one or more of the deficiencies described above.